64x16 Dot Matrix LED Display

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64x16 Dot Matrix LED Display
64x16-dot-matrix-display.jpg
Participants Noxiouspluk
Skills Arduino, Electronics, Knowledge sharing, Link gathering
Status Active
Niche
Purpose Electronics, fun, world domination
Tool No
Location Bij appy en Nox thuis aan de muur
Cost ~$15
Tool category

64x16 Dot Matrix LED Display

64x16-dot-matrix-display.jpg {{#if:No | [[Tool Owner::{{{ProjectParticipants}}} | }} {{#if:No | [[Tool Cost::~$15 | }}

The AliExpress advert

Story so far

So I bought this 64x16 display from AliExpress: https://www.aliexpress.com/item/P3-75-dot-matrix-led-module-3-75mm-high-clear-top1-for-text-display-304-60mm/32616683948.html

The problem was when one of us was streaming, there was no indication for the significant other in the house. Walking trough the camera view nude or screaming something obscene was a serious risk, so the idea was to get an 'ON AIR' sign.

After checking out various boring 'ON AIR' signs, I decided I'd rather have this fancy matrix and make it multi-purpose. It came in this morning and half a hour later I managed to have scrolling text on it with a modified version of this guy's code: https://www.instructables.com/id/64x16-RED-LED-Marquee/

Anyhow, this works - but I wanted also just non-scrolling text, an outline border and some other stuff - so I did some modifications and ended up with this for now (very not sorry, but this will mess up the layout of the wiki a bit perhaps):

 // Arduino 1.0.5 UNO R3
 #if (defined(__AVR__))
 #include <avr\pgmspace.h>
 #else
 #include <pgmspace.h>
 #endif
 
 // Connections to board
 const byte latchPin = 8;
 const byte clockPin = 12;
 const byte data_R1 = 10;
 const byte data_R2 = 11;
 const byte en_74138 = 2;
 const byte la_74138 = 3;
 const byte lb_74138 = 4;
 const byte lc_74138 = 5;
 const byte ld_74138 = 6;
 byte ScanRow = 0;
 unsigned long counter;
 
 byte buffer[128] = { // Display buffer (which is scanned by the interrupt timer) of 8x16 bytes  (nox-custom: added an outline border)
   0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
   0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01,
   0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01,
   0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01,
   0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01,
   0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01,
   0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01,
   0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01,
   0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01,
   0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01,
   0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01,
   0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01,
   0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01,
   0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01,
   0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01,
   0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
 };
 // ---------------------------------------------------------------------------------------------------
 // FONTS sourced from various locations on the internet
 // full ASCII character set (8x16) (1520 bytes)
 const uint8_t font8x16_basic[] PROGMEM = {
   /*   (32) */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
   /* ! (33) */ 0x00, 0x00, 0x00, 0x18, 0x3C, 0x3C, 0x3C, 0x18, 0x18, 0x18, 0x00, 0x18, 0x18, 0x00, 0x00, 0x00,
   /* " (34) */ 0x00, 0x00, 0x66, 0x66, 0x66, 0x24, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
   /* # (35) */ 0x00, 0x00, 0x00, 0x00, 0x6C, 0x6C, 0xFE, 0x6C, 0x6C, 0x6C, 0xFE, 0x6C, 0x6C, 0x00, 0x00, 0x00,
   /* $ (36) */ 0x00, 0x18, 0x18, 0x7C, 0xC6, 0xC2, 0xC0, 0x7C, 0x06, 0x06, 0x86, 0xC6, 0x7C, 0x18, 0x18, 0x00,
   /* % (37) */ 0x00, 0x00, 0x00, 0x00, 0x00, 0xC2, 0xC6, 0x0C, 0x18, 0x30, 0x60, 0xC6, 0x86, 0x00, 0x00, 0x00,
   /* & (38) */ 0x00, 0x00, 0x00, 0x38, 0x6C, 0x6C, 0x38, 0x76, 0xDC, 0xCC, 0xCC, 0xCC, 0x76, 0x00, 0x00, 0x00,
   /* ' (39) */ 0x00, 0x00, 0x30, 0x30, 0x30, 0x60, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
   /* ( (40) */ 0x00, 0x00, 0x00, 0x0C, 0x18, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x18, 0x0C, 0x00, 0x00, 0x00,
   /* ) (41) */ 0x00, 0x00, 0x00, 0x30, 0x18, 0x0C, 0x0C, 0x0C, 0x0C, 0x0C, 0x0C, 0x18, 0x30, 0x00, 0x00, 0x00,
   /* * (42) */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x66, 0x3C, 0xFF, 0x3C, 0x66, 0x00, 0x00, 0x00, 0x00, 0x00,
   /* + (43) */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x18, 0x18, 0x7E, 0x18, 0x18, 0x00, 0x00, 0x00, 0x00, 0x00,
   /* , (44) */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x18, 0x18, 0x18, 0x30, 0x00, 0x00,
   /* - (45) */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xFE, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
   /* . (46) */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x18, 0x18, 0x00, 0x00, 0x00,
   /* / (47) */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0x06, 0x0C, 0x18, 0x30, 0x60, 0xC0, 0x80, 0x00, 0x00, 0x00,
   /* 0 (48) */ 0x00, 0x00, 0x00, 0x3C, 0x66, 0xC3, 0xC3, 0xDB, 0xDB, 0xC3, 0xC3, 0x66, 0x3C, 0x00, 0x00, 0x00,
   /* 1 (49) */ 0x00, 0x00, 0x00, 0x18, 0x38, 0x78, 0x18, 0x18, 0x18, 0x18, 0x18, 0x18, 0x7E, 0x00, 0x00, 0x00,
   /* 2 (50) */ 0x00, 0x00, 0x00, 0x7C, 0xC6, 0x06, 0x0C, 0x18, 0x30, 0x60, 0xC0, 0xC6, 0xFE, 0x00, 0x00, 0x00,
   /* 3 (51) */ 0x00, 0x00, 0x00, 0x7C, 0xC6, 0x06, 0x06, 0x3C, 0x06, 0x06, 0x06, 0xC6, 0x7C, 0x00, 0x00, 0x00,
   /* 4 (52) */ 0x00, 0x00, 0x00, 0x0C, 0x1C, 0x3C, 0x6C, 0xCC, 0xFE, 0x0C, 0x0C, 0x0C, 0x1E, 0x00, 0x00, 0x00,
   /* 5 (53) */ 0x00, 0x00, 0x00, 0xFE, 0xC0, 0xC0, 0xC0, 0xFC, 0x06, 0x06, 0x06, 0xC6, 0x7C, 0x00, 0x00, 0x00,
   /* 6 (54) */ 0x00, 0x00, 0x00, 0x38, 0x60, 0xC0, 0xC0, 0xFC, 0xC6, 0xC6, 0xC6, 0xC6, 0x7C, 0x00, 0x00, 0x00,
   /* 7 (55) */ 0x00, 0x00, 0x00, 0xFE, 0xC6, 0x06, 0x06, 0x0C, 0x18, 0x30, 0x30, 0x30, 0x30, 0x00, 0x00, 0x00,
   /* 8 (56) */ 0x00, 0x00, 0x00, 0x7C, 0xC6, 0xC6, 0xC6, 0x7C, 0xC6, 0xC6, 0xC6, 0xC6, 0x7C, 0x00, 0x00, 0x00,
   /* 9 (57) */ 0x00, 0x00, 0x00, 0x7C, 0xC6, 0xC6, 0xC6, 0x7E, 0x06, 0x06, 0x06, 0x0C, 0x78, 0x00, 0x00, 0x00,
   /* : (58) */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x18, 0x18, 0x00, 0x00, 0x00, 0x18, 0x18, 0x00, 0x00, 0x00, 0x00,
   /* ; (59) */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x18, 0x18, 0x00, 0x00, 0x00, 0x18, 0x18, 0x30, 0x00, 0x00, 0x00,
   /* < (60) */ 0x00, 0x00, 0x00, 0x00, 0x06, 0x0C, 0x18, 0x30, 0x60, 0x30, 0x18, 0x0C, 0x06, 0x00, 0x00, 0x00,
   /* = (61) */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x7E, 0x00, 0x00, 0x7E, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
   /* > (62) */ 0x00, 0x00, 0x00, 0x00, 0x60, 0x30, 0x18, 0x0C, 0x06, 0x0C, 0x18, 0x30, 0x60, 0x00, 0x00, 0x00,
   /* ? (63) */ 0x00, 0x00, 0x00, 0x7C, 0xC6, 0xC6, 0x0C, 0x18, 0x18, 0x18, 0x00, 0x18, 0x18, 0x00, 0x00, 0x00,
   /* @ (64) */ 0x00, 0x00, 0x00, 0x00, 0x7C, 0xC6, 0xC6, 0xDE, 0xDE, 0xDE, 0xDC, 0xC0, 0x7C, 0x00, 0x00, 0x00,
   /* A (65) */ 0x00, 0x00, 0x00, 0x10, 0x38, 0x6C, 0xC6, 0xC6, 0xFE, 0xC6, 0xC6, 0xC6, 0xC6, 0x00, 0x00, 0x00,
   /* B (66) */ 0x00, 0x00, 0x00, 0xFC, 0x66, 0x66, 0x66, 0x7C, 0x66, 0x66, 0x66, 0x66, 0xFC, 0x00, 0x00, 0x00,
   /* C (67) */ 0x00, 0x00, 0x00, 0x3C, 0x66, 0xC2, 0xC0, 0xC0, 0xC0, 0xC0, 0xC2, 0x66, 0x3C, 0x00, 0x00, 0x00,
   /* D (68) */ 0x00, 0x00, 0x00, 0xF8, 0x6C, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x6C, 0xF8, 0x00, 0x00, 0x00,
   /* E (69) */ 0x00, 0x00, 0x00, 0xFE, 0x66, 0x62, 0x68, 0x78, 0x68, 0x60, 0x62, 0x66, 0xFE, 0x00, 0x00, 0x00,
   /* F (70) */ 0x00, 0x00, 0x00, 0xFE, 0x66, 0x62, 0x68, 0x78, 0x68, 0x60, 0x60, 0x60, 0xF0, 0x00, 0x00, 0x00,
   /* G (71) */ 0x00, 0x00, 0x00, 0x3C, 0x66, 0xC2, 0xC0, 0xC0, 0xDE, 0xC6, 0xC6, 0x66, 0x3A, 0x00, 0x00, 0x00,
   /* H (72) */ 0x00, 0x00, 0x00, 0xC6, 0xC6, 0xC6, 0xC6, 0xFE, 0xC6, 0xC6, 0xC6, 0xC6, 0xC6, 0x00, 0x00, 0x00,
   /* I (73) */ 0x00, 0x00, 0x00, 0x3C, 0x18, 0x18, 0x18, 0x18, 0x18, 0x18, 0x18, 0x18, 0x3C, 0x00, 0x00, 0x00,
   /* J (74) */ 0x00, 0x00, 0x00, 0x1E, 0x0C, 0x0C, 0x0C, 0x0C, 0x0C, 0xCC, 0xCC, 0xCC, 0x78, 0x00, 0x00, 0x00,
   /* K (75) */ 0x00, 0x00, 0x00, 0xE6, 0x66, 0x66, 0x6C, 0x78, 0x78, 0x6C, 0x66, 0x66, 0xE6, 0x00, 0x00, 0x00,
   /* L (76) */ 0x00, 0x00, 0x00, 0xF0, 0x60, 0x60, 0x60, 0x60, 0x60, 0x60, 0x62, 0x66, 0xFE, 0x00, 0x00, 0x00,
   /* M (77) */ 0x00, 0x00, 0x00, 0xC3, 0xE7, 0xFF, 0xFF, 0xDB, 0xC3, 0xC3, 0xC3, 0xC3, 0xC3, 0x00, 0x00, 0x00,
   /* N (78) */ 0x00, 0x00, 0x00, 0xC6, 0xE6, 0xF6, 0xFE, 0xDE, 0xCE, 0xC6, 0xC6, 0xC6, 0xC6, 0x00, 0x00, 0x00,
   /* O (79) */ 0x00, 0x00, 0x00, 0x7C, 0xC6, 0xC6, 0xC6, 0xC6, 0xC6, 0xC6, 0xC6, 0xC6, 0x7C, 0x00, 0x00, 0x00,
   /* P (80) */ 0x00, 0x00, 0x00, 0xFC, 0x66, 0x66, 0x66, 0x7C, 0x60, 0x60, 0x60, 0x60, 0xF0, 0x00, 0x00, 0x00,
   /* Q (81) */ 0x00, 0x00, 0x00, 0x7C, 0xC6, 0xC6, 0xC6, 0xC6, 0xC6, 0xC6, 0xD6, 0xDE, 0x7C, 0x0C, 0x0E, 0x00,
   /* R (82) */ 0x00, 0x00, 0x00, 0xFC, 0x66, 0x66, 0x66, 0x7C, 0x6C, 0x66, 0x66, 0x66, 0xE6, 0x00, 0x00, 0x00,
   /* S (83) */ 0x00, 0x00, 0x00, 0x7C, 0xC6, 0xC6, 0x60, 0x38, 0x0C, 0x06, 0xC6, 0xC6, 0x7C, 0x00, 0x00, 0x00,
   /* T (84) */ 0x00, 0x00, 0x00, 0xFF, 0xDB, 0x99, 0x18, 0x18, 0x18, 0x18, 0x18, 0x18, 0x3C, 0x00, 0x00, 0x00,
   /* U (85) */ 0x00, 0x00, 0x00, 0xC6, 0xC6, 0xC6, 0xC6, 0xC6, 0xC6, 0xC6, 0xC6, 0xC6, 0x7C, 0x00, 0x00, 0x00,
   /* V (86) */ 0x00, 0x00, 0x00, 0xC3, 0xC3, 0xC3, 0xC3, 0xC3, 0xC3, 0xC3, 0x66, 0x3C, 0x18, 0x00, 0x00, 0x00,
   /* W (87) */ 0x00, 0x00, 0x00, 0xC3, 0xC3, 0xC3, 0xC3, 0xC3, 0xDB, 0xDB, 0xFF, 0x66, 0x66, 0x00, 0x00, 0x00,
   /* X (88) */ 0x00, 0x00, 0x00, 0xC3, 0xC3, 0x66, 0x3C, 0x18, 0x18, 0x3C, 0x66, 0xC3, 0xC3, 0x00, 0x00, 0x00,
   /* Y (89) */ 0x00, 0x00, 0x00, 0xC3, 0xC3, 0xC3, 0x66, 0x3C, 0x18, 0x18, 0x18, 0x18, 0x3C, 0x00, 0x00, 0x00,
   /* Z (90) */ 0x00, 0x00, 0x00, 0xFF, 0xC3, 0x86, 0x0C, 0x18, 0x30, 0x60, 0xC1, 0xC3, 0xFF, 0x00, 0x00, 0x00,
   /* [ (91) */ 0x00, 0x00, 0x00, 0x3C, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x3C, 0x00, 0x00, 0x00,
   /* \ (92) */ 0x00, 0x00, 0x00, 0x00, 0x80, 0xC0, 0xE0, 0x70, 0x38, 0x1C, 0x0E, 0x06, 0x02, 0x00, 0x00, 0x00,
   /* ] (93) */ 0x00, 0x00, 0x00, 0x3C, 0x0C, 0x0C, 0x0C, 0x0C, 0x0C, 0x0C, 0x0C, 0x0C, 0x3C, 0x00, 0x00, 0x00,
   /* ^ (94) */ 0x00, 0x10, 0x38, 0x6C, 0xC6, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
   /* _ (95) */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xFF, 0x00,
   /* ` (96) */ 0x00, 0x30, 0x30, 0x18, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
   /* a (97) */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x78, 0x0C, 0x7C, 0xCC, 0xCC, 0xCC, 0x76, 0x00, 0x00, 0x00,
   /* b (98) */ 0x00, 0x00, 0x00, 0xE0, 0x60, 0x60, 0x78, 0x6C, 0x66, 0x66, 0x66, 0x66, 0x7C, 0x00, 0x00, 0x00,
   /* c (99) */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x7C, 0xC6, 0xC0, 0xC0, 0xC0, 0xC6, 0x7C, 0x00, 0x00, 0x00,
   /* d (100) */ 0x00, 0x00, 0x00, 0x1C, 0x0C, 0x0C, 0x3C, 0x6C, 0xCC, 0xCC, 0xCC, 0xCC, 0x76, 0x00, 0x00, 0x00,
   /* e (101) */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x7C, 0xC6, 0xFE, 0xC0, 0xC0, 0xC6, 0x7C, 0x00, 0x00, 0x00,
   /* f (102) */ 0x00, 0x00, 0x00, 0x38, 0x6C, 0x64, 0x60, 0xF0, 0x60, 0x60, 0x60, 0x60, 0xF0, 0x00, 0x00, 0x00,
   /* g (103) */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x76, 0xCC, 0xCC, 0xCC, 0xCC, 0xCC, 0x7C, 0x0C, 0xCC, 0x78,
   /* h (104) */ 0x00, 0x00, 0x00, 0xE0, 0x60, 0x60, 0x6C, 0x76, 0x66, 0x66, 0x66, 0x66, 0xE6, 0x00, 0x00, 0x00,
   /* i (105) */ 0x00, 0x00, 0x00, 0x18, 0x18, 0x00, 0x38, 0x18, 0x18, 0x18, 0x18, 0x18, 0x3C, 0x00, 0x00, 0x00,
   /* j (106) */ 0x00, 0x00, 0x00, 0x06, 0x06, 0x00, 0x0E, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x66, 0x66, 0x3C,
   /* k (107) */ 0x00, 0x00, 0x00, 0xE0, 0x60, 0x60, 0x66, 0x6C, 0x78, 0x78, 0x6C, 0x66, 0xE6, 0x00, 0x00, 0x00,
   /* l (108) */ 0x00, 0x00, 0x00, 0x38, 0x18, 0x18, 0x18, 0x18, 0x18, 0x18, 0x18, 0x18, 0x3C, 0x00, 0x00, 0x00,
   /* m (109) */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xE6, 0xFF, 0xDB, 0xDB, 0xDB, 0xDB, 0xDB, 0x00, 0x00, 0x00,
   /* n (110) */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xDC, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x00, 0x00, 0x00,
   /* o (111) */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x7C, 0xC6, 0xC6, 0xC6, 0xC6, 0xC6, 0x7C, 0x00, 0x00, 0x00,
   /* p (112) */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xDC, 0x66, 0x66, 0x66, 0x66, 0x66, 0x7C, 0x60, 0x60, 0xF0,
   /* q (113) */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x76, 0xCC, 0xCC, 0xCC, 0xCC, 0xCC, 0x7C, 0x0C, 0x0C, 0x1E,
   /* r (114) */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xDC, 0x76, 0x66, 0x60, 0x60, 0x60, 0xF0, 0x00, 0x00, 0x00,
   /* s (115) */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x7C, 0xC6, 0x60, 0x38, 0x0C, 0xC6, 0x7C, 0x00, 0x00, 0x00,
   /* t (116) */ 0x00, 0x00, 0x00, 0x10, 0x30, 0x30, 0xFC, 0x30, 0x30, 0x30, 0x30, 0x36, 0x1C, 0x00, 0x00, 0x00,
   /* u (117) */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xCC, 0xCC, 0xCC, 0xCC, 0xCC, 0xCC, 0x76, 0x00, 0x00, 0x00,
   /* v (118) */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xC3, 0xC3, 0xC3, 0xC3, 0x66, 0x3C, 0x18, 0x00, 0x00, 0x00,
   /* w (119) */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xC3, 0xC3, 0xC3, 0xDB, 0xDB, 0xFF, 0x66, 0x00, 0x00, 0x00,
   /* x (120) */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xC3, 0x66, 0x3C, 0x18, 0x3C, 0x66, 0xC3, 0x00, 0x00, 0x00,
   /* y (121) */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xC6, 0xC6, 0xC6, 0xC6, 0xC6, 0xC6, 0x7E, 0x06, 0x0C, 0xF8,
   /* z (122) */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xFE, 0xCC, 0x18, 0x30, 0x60, 0xC6, 0xFE, 0x00, 0x00, 0x00,
   /* { (123) */ 0x00, 0x00, 0x00, 0x0E, 0x18, 0x18, 0x18, 0x70, 0x18, 0x18, 0x18, 0x18, 0x0E, 0x00, 0x00, 0x00,
   /* | (124) */ 0x00, 0x00, 0x00, 0x18, 0x18, 0x18, 0x18, 0x00, 0x18, 0x18, 0x18, 0x18, 0x18, 0x00, 0x00, 0x00,
   /* } (125) */ 0x00, 0x00, 0x00, 0x70, 0x18, 0x18, 0x18, 0x0E, 0x18, 0x18, 0x18, 0x18, 0x70, 0x00, 0x00, 0x00,
   /* ~ (126) */ 0x00, 0x00, 0x00, 0x76, 0xDC, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
   /* BLK(127)*/ 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
 };
 // Routine to print a single character in one of 8 columns
 // Inputs:
 // x is one of (0,16,24,32,40,48,56),
 // y (0 to 16 or 24 depending upon font size),
 // n is either (0 to 9) or an ascii value,
 // font=0 for big font, 2 for small font,
 // inverse is true for an inverted character
 void drawChar(uint16_t x, uint16_t y, byte n, byte font, boolean inverse) {
   byte charbytes[16], fontrows, xover8 = x >> 3;
   int index;
   if (0 != (x % 8)) return;    // x not a multiple of 8
   if ((n > 9) && (n < 32)) return; // invalid character
   if (font == 0) fontrows = 16; else fontrows = 8;
   if ((n >= 0) && (n <= 9)) index = (n + 16) * fontrows; else index = (n - 32) * fontrows; // go to the right code for this character
 
   // addressing start at buffer and add y (rows) * (WIDTH is 64 so WIDTH/8) is 8 plus (x / 8) is 0 to 7
   byte *pDst = buffer + (y << 3) + xover8;
   for (byte i = 0; i < fontrows; i++) { // fill up the charbytes array with the right bits
     if (font == 0) charbytes[i] = pgm_read_byte(&(font8x16_basic[index + i]));
     // reverse bit order for fonts 0 and 1
     if (font != 0) {
       charbytes[i] = (charbytes[i] & 0xF0) >> 4 | (charbytes[i] & 0x0F) << 4;
       charbytes[i] = (charbytes[i] & 0xCC) >> 2 | (charbytes[i] & 0x33) << 2;
       charbytes[i] = (charbytes[i] & 0xAA) >> 1 | (charbytes[i] & 0x55) << 1;
     };
     if (inverse) charbytes[i] = ~charbytes[i];
   };
   const byte *pSrc = charbytes; // point at the first set of 8 pixels
   for (byte i = 0; i < fontrows; i++) {
 
     *pDst |= *pSrc;  //nox-custom: OR added to draw OVER buffer instead of replace
 
     //nox-custom: add a line above and below chars
     //if ( i == 1 || i == 14) {
     //  *pDst = byte(0xFF);
     //} //end nox-custom
 
     pDst += 8;         // go to next row on buffer
     pSrc++;            // go to next set of 8 pixels in character
   }
 };
 
 void moveLeft(byte pixels, byte rowstart, byte rowstop) { // routine to move certain rows on the screen "pixels" pixels to the left
   byte row, column;
   short unsigned int address;
   for (column = 0; column < 8; column++) {
     for (row = rowstart; row < rowstop; row++) {
       address = (row << 3) + column; /// right here!
       if (column == 7)
         buffer[address] = buffer[address] << pixels; // shuffle pixels left on last column and fill with a blank
       else {                // shuffle pixels left and add leftmost pixels from next column
         byte incomingchar = buffer[address + 1];
         buffer[address] = buffer[address] << pixels;
         for (byte x = 0; x < pixels; x++) {
           buffer[address] += ((incomingchar & (128 >> x)) >> (7 - x)) << (pixels - x - 1);
         };
       }
     }
   }
 };
 
 
 
 void shiftOut(byte row) { // fast routine to shove out 8 columns into two rows via board's shift registers
   for (byte column = 0; column < 8; column++) {
     byte index = column + (row << 3);
     for (byte i = 0; i < 8; i++) {
       PORTB &= ~(3 << (data_R1 - 8));                            // data_R2 is LOW; data_R1 is LOW;
       PORTB &= ~(1 << (clockPin - 8));                           // digitalWrite(clockPin,LOW);
       PORTB |= !((buffer[index] >> (7 - i)) & 0x01) << (data_R1 - 8); // top set of rows
       PORTB |= !((buffer[index + 128] >> (7 - i)) & 0x01) << (data_R2 - 8); // bottom set of rows
       PORTB |= 1 << (clockPin - 8);                              // digitalWrite(clockPin,HIGH);
     };
   };
 };
 
 ISR(TIMER2_COMPA_vect) {
   cli();
   digitalWrite(en_74138, HIGH);     // Turn off display
   shiftOut(ScanRow);                // Shift out 8 columns
   digitalWrite(latchPin, LOW);
   digitalWrite(latchPin, HIGH);
   PORTD = (ScanRow << 3) | (PORTD & 0X87); // Highlight row: pins 3 4 5 6 (la_74138 lb_74138 lc_74138 ld_74138)
   digitalWrite(en_74138, LOW);     // Turn on display
   ScanRow++;                       // Do the next pair of rows next time this routine is called
   if (ScanRow == 16) ScanRow = 0;
   sei();
 };
 
 void setup() {
 
   // Set up Timer2 as the scanning interrupt timer
   cli(); // clear interrupts
   TCCR2A = 0; TCCR2B = 0; TCNT2  = 0;
   TCCR2B |= (1 << CS12) | (1 << CS10);     // Set 1024 prescaler
   // 160Hz scan rate = 10 frames/second (16 pairs of rows)
   OCR2A = 97;  // 97 = (16,000,000 / (1024*160)) - 1
   TCCR2A |= (1 << WGM21); TIMSK2 |= (1 << OCIE2A);
 
   pinMode(latchPin, OUTPUT);  pinMode(clockPin, OUTPUT);
   pinMode(data_R1, OUTPUT);   pinMode(data_R2, OUTPUT);
 
   pinMode(en_74138, OUTPUT);
   pinMode(la_74138, OUTPUT);  pinMode(lb_74138, OUTPUT);
   pinMode(lc_74138, OUTPUT);  pinMode(ld_74138, OUTPUT);
 
   digitalWrite(en_74138, LOW);
   digitalWrite(data_R1, HIGH); digitalWrite(data_R2, HIGH);
   counter = millis();
   sei(); //allow interrupts
 
   //nox-custom: draw " ON AIR "
   drawChar(0, 0, char(' '), 0, false);
   drawChar(8, 0, char('O'), 0, false);
   drawChar(16, 0, char('N'), 0, false);
   drawChar(24, 0, char(' '), 0, false);
   drawChar(32, 0, char('A'), 0, false);
   drawChar(40, 0, char('I'), 0, false);
   drawChar(48, 0, char('R'), 0, false);
   drawChar(56, 0, char(' '), 0, false);
   //end nox-custom
 
 };
 
 void loop() {
   /*
     //Insert message here ("message ")
     const char message[] = "This is a test by NoxiousPluK         ";
     static int count = 0;
 
     //display next character of message
     drawChar(56,0,message[count%(sizeof(message)-1)],0,false);
     count = (count + 1);
 
     //move the text 8 pixels to the left
     for (byte i=0; i<4; i++) {
     delay(80);
     moveLeft(2,1,32);
     };
   */
 };
 

Works pretty well for my goals so far, and more to come!

I've identified some of the chips on the back, but they're mainly shift registers and some mosfets. Not extremely interesting.

Ideas and goals

I want to make it wireless using an ESP8266 or something alike, and run a simple API for my needs. I also want to use it as a pizza countdown timer for example.

 
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